Fityk

Fityk version 1.3.1 is a highly efficient, user-friendly, open source software designed for nonlinear curve fitting and data analysis. This tool is especially popular among scientists for tasks such as powder diffraction, chromatography, photoluminescence, and infrared and Raman spectroscopy. However, it also excels in fitting analytical functions to virtually any type of data. Fityk allows users to perform intricate operations like data visualization, background subtraction, and separation of overlapping peaks. Key features include least squares fitting using the Levenberg-Marquardt algorithm and the use of macros to automate repetitive tasks.

Developed by Marcin Wojdyr, the software is available to download as fityk.exe and cfityk.exe files, both with a modest file size of 5 MB. Its versatility is evident as it supports a wide range of operating systems including Windows 2000, XP, XP Professional, Vista, 7, 8, 10, and 11.

Advanced users will appreciate Fityk's dedicated support for fitting bell-shaped functions such as Gaussian, Lorentzian, Pearson 7, Voigt, Pseudo-Voigt, and Doniach-Sunjic. The application serves not only scientists but fits well in the broader Education category, specifically within Science Tools.

In addition to the latest 1.3.1 version, previous iterations such as 1.3, 0.9, and 0.8 are also noteworthy. As an open source utility, users can freely modify and distribute the software, thus enhancing its scope and functionality.

Pros:

• Free and open source.
• Supports a wide array of OS versions.
• Robust feature set for scientific data analysis.
• User-friendly with macro support for task automation.

Cons:

• May have a steeper learning curve for new users.
• Limited documentation might require reliance on community support.

You may want to check out more software, such as Agelong Tree, ChaosPro or Distance, which might be related to Fityk.